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Title: Mechanistic Study of Nitric Oxide Reduction by Hydrogen on Pt(100) (I): A DFT Analysis of the Reaction Network

Periodic, self-consistent density functional theory (DFT-GGA, PW91) calculations are used to study the reaction mechanism for nitric oxide (NO) reduction by hydrogen (H 2) on Pt(100). Energetics of various N–O activation paths, including both direct and hydrogen-assisted N–O bond-breaking paths, and the formation of three different N-containing products (N 2, N 2O, and NH3), are systematically studied. On the basis of our analysis, NO* dissociation has a lower barrier than NO* hydrogenation to HNO* or NOH*, and therefore, the direct NO dissociation path is predicted to dominate N–O activation on clean Pt(100). The reaction of atomic N* with N* and NO* is proposed as the mechanism for N 2 and N 2O formation, respectively. NH 3 formation from N* via three successive hydrogenation steps is also studied and is found to be kinetically more difficult than N 2 and N 2O formation from N*. Finally, NO adsorption phase diagrams on Pt(100) are constructed, and these phase diagrams suggest that, at low temperatures (e.g., 400 K), the Pt(100) surface may be covered by half a monolayer of NO. We propose that high NO coverage might affect the NO + H 2 reaction mechanism, and therefore, one should explicitly take the NOmore » coverage into consideration in first-principles studies to determine the reaction mechanism on catalyst surfaces under reaction conditions. In conclusion, a detailed analysis of high NO coverage effects on the reaction mechanism will be presented in a separate contribution.« less
Authors:
 [1] ; ORCiD logo [1]
  1. Univ. of Wisconsin-Madison, Madison, WI (United States)
Publication Date:
Grant/Contract Number:
FG02-05ER15731
Type:
Accepted Manuscript
Journal Name:
Journal of Physical Chemistry. B, Condensed Matter, Materials, Surfaces, Interfaces and Biophysical Chemistry
Additional Journal Information:
Journal Volume: 122; Journal Issue: 2; Journal ID: ISSN 1520-6106
Publisher:
American Chemical Society
Research Org:
Univ. of Wisconsin-Madison, Madison, WI (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
Contributing Orgs:
EMSL at Pacific Northwest National Laboratory (PNNL); the Center for Nanoscale Materials at Argonne National Laboratory (ANL); and the National Energy Research Scientific Computing Center (NERSC)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; 36 MATERIALS SCIENCE
OSTI Identifier:
1397268
Alternate Identifier(s):
OSTI ID: 1355944